The present invention relates to a hot gas engine, for instance the Stirling engine, in which a mixture of fuel and air is injected into the combustion chamber to supply external heat to the working medium in the engine. The fresh air is preheated in a heat exchanger by heat exchange with the use of exhaust gases from which is provided with chamber, the combustion means for the admission intake of the thus preheated fresh air and, which intake means are connected with the fresh air outlet of the heat exchanger through a channel.
According to the working principle of such hot gas engines the completely enclosed working medium is circulated on the one hand through a heater associated with the and on the, through a cooler as well as a regenerator situated therebetween. Water is usually used as cooling medium. To obtain optimum efficiency and performance of a hot gas engine, the cooling water temperature should be as low as possible, and consequently the difference between the temperatures of the entering and the leaving cooling water will also be very small. For this reason the cooling water in the hot gas engine cannot be used for heating purposes without substantially increasing the cooling water temperature and said temperature difference with consequent great losses in engine efficiency and performance. This is in contrast to the high temperature of the cooling water from the cooling gaskets in conventional explosion engines.
Heating of a space in conjunction with a hot gas engine, for instance a boat cabin or the interior of a vehicle, must thus be accomplished by the use of a special heating equipment such as a space heater, or other separate heating device.